The purpose of this project is to investigate the nature of implicit learning in children with Specific Language Impairment (SLI). A key question is whether the language impairments seen in these children are due to impaired cognitive processing mechanisms or are a representational deficit in a specific grammar module. Recently, it has been proposed that: (1) the syntax, morphology, auditory processing, and working memory deficits seen in children with SLI are due instead to a procedural implicit learning deficit, and (2) the relatively spared vocabulary abilities in children with SLI suggests an intact declarative learning system that may function as a compensatory mechanism in their language acquisition. Procedural memory is used in the learning of sequential, cognitive, and perceptual motor skills. Recent work suggests, however, that SLI may instead be a domain general implicit learning impairment that extends beyond procedural learning to include category learning, statistical, and artificial grammar learning, and that this implicit learning impairment may extend beyond the perceptual motor system to include the auditory and visual modalities as well. The purpose of this project is to determine if implicit learning in children with SLI is a domain general or domain specific impairment. A total of 170 children will participate in this 5-year project, including 85 children with SLI, 7-9 years of age and 85 normal language controls (CA) matched on chronological age, nonverbal IQ, and maternal education. A total of 9 implicit learning studies are proposed. Studies 1-3 will examine directly whether implicit learning in children with SLI (N = 45) is impaired for implicit category, statistical, and artificial grammar learning on tasks designed to have auditory, visual, and perceptual motor isomorphs as compared to CA controls (N = 45). Studies 4-6 will examine the nature and time course of implicit category, statistical, and artificial grammar learning in the auditory modality and ask if this knowledge transfers to visual and perceptual motor modalities in children with SLI (N = 40) and CA controls (N = 40). Studies 7-9 ask whether implicit learning predicts not only syntax and morphology knowledge, but also vocabulary knowledge, in both children with SLI (N = 85) and CA controls (N = 85). Theoretically, these studies extend our understanding of linguistic and nonlinguistic deficits in children with SLI by clarifying the extent to which modality specific or general implicit learning deficits may contribute to the language impairments seen in these children. Clinically, these studies will provide valuable insights into the nature and intensity of intervention that may be required to facilitate the implicit learning of abstract representations in children with SLI, and will lead to the development of effective intervention models for school-aged children with SLI who are at risk for severe difficulties in communication, reading, writing, and academic failure. PUBLIC HEALTH RELEVANCE The purpose of this project is to investigate implicit learning in children with Specific Language Impairment (SLI). There is evidence to suggest that children with SLI may have a domain general deficit in implicit learning. Implicit learning is gradual, occurring on an ongoing basis across multiple trials or exemplars, and appears to be the mechanism by which language is learned in typically developing children. The studies proposed in this project address the gap in our understanding of implicit learning abilities in children with SLI by directly examining the extent to which children with SLI may have a modality general implicit learning impairment. The findings from this research will provide valuable insights into the nature and intensity of intervention that may be required to facilitate the language learning in children with language impairments, and will aid the development of effective intervention models for school-aged children with language impairments who are at risk for severe difficulties in communication, reading, writing, and academic failure.